oauth_login

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations cover the safety profile (not read-only, open-world, non-destructive), and the description adds a non-obvious failure mode with a specific HTTP status and internal error code plus remediation. That is meaningful behavioral disclosure beyond the annotations, though it says nothing about token lifetime, response payload, or rate limits.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three sentences, front-loaded with the action, then the scope constraint, then the edge case. Every sentence carries distinct, actionable information with no filler.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a two-parameter auth tool with no output schema, the description covers the credential type, the provider limitation, and the main recovery path. It leaves the success response shape and token persistence unstated, but nothing critical to correct invocation is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% and both parameters are documented in-schema, so the schema already carries the semantics. The description only adds that the same idToken is reused for associate_email; baseline 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb+resource ('log in or sign up') and the credential type (Google ID token), plus an explicit scope limitation ('Google OIDC only — no Apple/GitHub branch'). It doesn't explicitly differentiate itself from the sibling auth_login or managed_sign_in, so it stops short of a 5.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives a concrete conditional flow: on 404/internal code 108, call associate_email first with the same idToken before retrying. That is real when-to-use guidance. It does not, however, say when to pick this over auth_login or managed_sign_in.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.